I'm not sure if my friends and I invented this term or if we've stolen it from somewhere else. I'd suspect the latter of the two. Essentially, when a female acquaintance does something ballsy, we take note of the size of her schlong, comparing it to our own. This is all on a metaphorical level, as obviously she has no schlong to enter into the equation. A woman who frequently compares favourably is well on her way to having the biggest cock of any girl we know.

We probably didn't think this out too well before introducing it to the mainstream of our friends. It is a mild ego battering to realise that many of the women in your life have cocks that put your own to shame.

Please note that having the biggest cock of any girl we know does not in any way diminish the femininity of the subject. If anything, it is enhanced.